* changes:
fix(libc): remove __putchar alias
fix(console): correct scopes for console symbols
fix(auth): use NULL instead of 0 for pointer check
fix(io): compare function pointers with NULL
fix(fdt-wrappers): use correct prototypes
This was triggered by sparse tool:
drivers/auth/mbedtls/mbedtls_x509_parser.c:481:42: warning:
Using plain integer as NULL pointer
Signed-off-by: Yann Gautier <yann.gautier@st.com>
Change-Id: I392316c2a81ef8da7597e35f136e038f152d19d1
get_ext() does not check the return value of the various mbedtls_*
functions, as cert_parse() is assumed to have guaranteed that they will
always succeed. However, it passes the end of an extension as the end
pointer to these functions, whereas cert_parse() passes the end of the
TBSCertificate. Furthermore, cert_parse() does *not* check that the
contents of the extension have the same length as the extension itself.
Before fd37982a19 ("fix(auth): forbid junk after extensions"),
cert_parse() also does not check that the extension block extends to the
end of the TBSCertificate.
This is a problem, as mbedtls_asn1_get_tag() leaves *p and *len
undefined on failure. In practice, this results in get_ext() continuing
to parse at different offsets than were used (and validated) by
cert_parse(), which means that the in-bounds guarantee provided by
cert_parse() no longer holds.
This patch fixes the remaining flaw by enforcing that the contents of an
extension are the same length as the extension itself.
Change-Id: Id4570f911402e34d5d6c799ae01a01f184c68d7c
Signed-off-by: Demi Marie Obenour <demiobenour@gmail.com>
Signed-off-by: Sandrine Bailleux <sandrine.bailleux@arm.com>
This makes the code a little bit smaller. No functional change
intended.
Change-Id: I794d2927fcd034a79e29c9bba1f8e4410203f547
Signed-off-by: Demi Marie Obenour <demiobenour@gmail.com>
Certificates must not allow trailing junk after them.
Change-Id: Ie33205fb051fc63af5b72c326822da7f62eec1d1
Signed-off-by: Demi Marie Obenour <demiobenour@gmail.com>
This is already checked by the crypto module or by mbedTLS, but checking
it in the X.509 parser is harmless.
Change-Id: Ifdbe3b4c6d04481bb8e93106ee04b49a70f50d5d
Signed-off-by: Demi Marie Obenour <demiobenour@gmail.com>
Since the two instances of the signature algorithm in a certificate must
be bitwise identical, it is not necessary to parse both of them.
Instead, it suffices to parse one of them, and then check that the other
fits in the remaining buffer space and is equal to the first.
Change-Id: Id0a0663165f147879ac83b6a540378fd4873b0dd
Signed-off-by: Demi Marie Obenour <demiobenour@gmail.com>
This reduces the likelihood of future problems later.
Change-Id: Ia748b6ae31a7a48f17ec7f0fc08310a50cd1b135
Signed-off-by: Demi Marie Obenour <demiobenour@gmail.com>
X.509 and RFC5280 allow omitting the extensions entirely, but require
that if the extensions field is present at all, it must contain at least
one certificate. TF-A already requires the extensions to be present,
but allows them to be empty. However, a certificate with an empty
extensions field will always fail later on, as the extensions contain
the information needed to validate the next stage in the boot chain.
Therefore, it is simpler to require the extension field to be present
and contain at least one extension. Also add a comment explaining why
the extensions field is required, even though it is OPTIONAL in the
ASN.1 syntax.
Change-Id: Ie26eed8a7924bf50937a6b27ccdf7cc9a390588d
Signed-off-by: Demi Marie Obenour <demiobenour@gmail.com>
The extensions must use all remaining bytes in the TBSCertificate.
Change-Id: Idf48f7168e146d050ba62dbc732638946fcd6c92
Signed-off-by: Demi Marie Obenour <demiobenour@gmail.com>
v1 and v2 are forbidden as at least one extension is required. Instead
of actually parsing the version number, just compare it with a
hard-coded string.
Change-Id: Ib8fd34304a0049787db77ec8c2359d0930cd4ba1
Signed-off-by: Demi Marie Obenour <demiobenour@gmail.com>
Correct the warning due to comparison between signed and
unsigned variable.
drivers/auth/mbedtls/mbedtls_x509_parser.c: In function 'get_ext':
drivers/auth/mbedtls/mbedtls_x509_parser.c:120:30:
error: comparison of integer expressions of different
signedness: 'int' and 'size_t' {aka 'unsigned int'}
[-Werror=sign-compare]
120 | if ((oid_len == strlen(oid_str)) && !strcmp(oid, oid_str)) {
| ^~
Change-Id: Ic12527f5f92a34e925bee3047c168eacf5e99d8a
Signed-off-by: Nicolas Toromanoff <nicolas.toromanoff@st.com>
Enforce full include path for includes. Deprecate old paths.
The following folders inside include/lib have been left unchanged:
- include/lib/cpus/${ARCH}
- include/lib/el3_runtime/${ARCH}
The reason for this change is that having a global namespace for
includes isn't a good idea. It defeats one of the advantages of having
folders and it introduces problems that are sometimes subtle (because
you may not know the header you are actually including if there are two
of them).
For example, this patch had to be created because two headers were
called the same way: e0ea0928d5 ("Fix gpio includes of mt8173 platform
to avoid collision."). More recently, this patch has had similar
problems: 46f9b2c3a2 ("drivers: add tzc380 support").
This problem was introduced in commit 4ecca33988 ("Move include and
source files to logical locations"). At that time, there weren't too
many headers so it wasn't a real issue. However, time has shown that
this creates problems.
Platforms that want to preserve the way they include headers may add the
removed paths to PLAT_INCLUDES, but this is discouraged.
Change-Id: I39dc53ed98f9e297a5966e723d1936d6ccf2fc8f
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>
To make software license auditing simpler, use SPDX[0] license
identifiers instead of duplicating the license text in every file.
NOTE: Files that have been imported by FreeBSD have not been modified.
[0]: https://spdx.org/
Change-Id: I80a00e1f641b8cc075ca5a95b10607ed9ed8761a
Signed-off-by: dp-arm <dimitris.papastamos@arm.com>
This reverts commit b621fb503c.
Because of the Trusted Firmware design, timing-safe functions are not
needed. Using them may be misleading as it could be interpreted as being
a protection against private data leakage, which isn't the case here.
For each image, the SHA-256 hash is calculated. Some padding is appended
and the result is encrypted with a private key using RSA-2048. This is
the signature of the image. The public key is stored along with BL1 in
read-only memory and the encrypted hash is stored in the FIP.
When authenticating an image, the TF decrypts the hash stored in the FIP
and recalculates the hash of the image. If they don't match, the boot
sequence won't continue.
A constant-time comparison does not provide additional security as all
the data involved in this process is already known to any attacker.
There is no private data that can leaked through a timing attack when
authenticating an image.
`timingsafe_bcmp()` is kept in the codebase because it could be useful
in the future.
Change-Id: I44bdcd58faa586a050cc89447e38c142508c9888
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>
Replace all use of memset by zeromem when zeroing moderately-sized
structure by applying the following transformation:
memset(x, 0, sizeof(x)) => zeromem(x, sizeof(x))
As the Trusted Firmware is compiled with -ffreestanding, it forbids the
compiler from using __builtin_memset and forces it to generate calls to
the slow memset implementation. Zeromem is a near drop in replacement
for this use case, with a more efficient implementation on both AArch32
and AArch64.
Change-Id: Ia7f3a90e888b96d056881be09f0b4d65b41aa79e
Signed-off-by: Douglas Raillard <douglas.raillard@arm.com>
To avoid timing side-channel attacks, it is needed to use a constant
time memory comparison function when comparing hashes. The affected
code only cheks for equality so it isn't needed to use any variant of
memcmp(), bcmp() is enough.
Also, timingsafe_bcmp() is as fast as memcmp() when the two compared
regions are equal, so this change incurrs no performance hit in said
case. In case they are unequal, the boot sequence wouldn't continue as
normal, so performance is not an issue.
Change-Id: I1c7c70ddfa4438e6031c8814411fef79fd3bb4df
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>
In mbedtls_x509_parser.c there are some static arrays that are filled
during the integrity check and then read whenever an authentication
parameter is requested. However, they aren't cleared in case of an
integrity check failure, which can be problematic from a security
point of view. This patch clears these arrays in the case of failure.
Change-Id: I9d48f5bc71fa13e5a75d6c45b5e34796ef13aaa2
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>
This patch adds support for non-volatile counter authentication to
the Authentication Module. This method consists of matching the
counter values provided in the certificates with the ones stored
in the platform. If the value from the certificate is lower than
the platform, the boot process is aborted. This mechanism protects
the system against rollback.
The TBBR CoT has been updated to include this method as part of the
authentication process. Two counters are used: one for the trusted
world images and another for the non trusted world images.
** NEW PLATFORM APIs (mandatory when TBB is enabled) **
int plat_get_nv_ctr(void *cookie, unsigned int *nv_ctr);
This API returns the non-volatile counter value stored
in the platform. The cookie in the first argument may be
used to select the counter in case the platform provides
more than one (i.e. TBSA compliant platforms must provide
trusted and non-trusted counters). This cookie is specified
in the CoT.
int plat_set_nv_ctr(void *cookie, unsigned int nv_ctr);
This API sets a new counter value. The cookie may be
used to select the counter to be updated.
An implementation of these new APIs for ARM platforms is also
provided. The values are obtained from the Trusted Non-Volatile
Counters peripheral. The cookie is used to pass the extension OID.
This OID may be interpreted by the platform to know which counter
must return. On Juno, The trusted and non-trusted counter values
have been tied to 31 and 223, respectively, and cannot be modified.
** IMPORTANT **
THIS PATCH BREAKS THE BUILD WHEN TRUSTED_BOARD_BOOT IS ENABLED. THE
NEW PLATFORM APIs INTRODUCED IN THIS PATCH MUST BE IMPLEMENTED IN
ORDER TO SUCCESSFULLY BUILD TF.
Change-Id: Ic943b76b25f2a37f490eaaab6d87b4a8b3cbc89a
The mbed TLS library has introduced some changes in the API from
the 1.3.x to the 2.x releases. Using the 2.x releases requires
some changes to the crypto and transport modules.
This patch updates both modules to the mbed TLS 2.x API.
All references to the mbed TLS library in the code or documentation
have been updated to 'mbed TLS'. Old references to PolarSSL have
been updated to 'mbed TLS'.
User guide updated to use mbed TLS 2.2.0.
NOTE: moving up to mbed TLS 2.x from 1.3.x is not backward compatible.
Applying this patch will require an mbed TLS 2.x release to be used.
Also note that the mbed TLS license changed to Apache version 2.0.
Change-Id: Iba4584408653cf153091f2ca2ee23bc9add7fda4
This patch adds the following mbedTLS based libraries:
* Cryptographic library
It is used by the crypto module to verify a digital signature
and a hash. This library relies on mbedTLS to perform the
cryptographic operations. mbedTLS sources must be obtained
separately.
Two key algorithms are currently supported:
* RSA-2048
* ECDSA-SECP256R1
The platform is responsible for picking up the required
algorithm by defining the 'MBEDTLS_KEY_ALG' variable in the
platform makefile. Available options are:
* 'rsa' (for RSA-2048) (default option)
* 'ecdsa' (for ECDSA-SECP256R1)
Hash algorithm currently supported is SHA-256.
* Image parser library
Used by the image parser module to extract the authentication
parameters stored in X509v3 certificates.
Change-Id: I597c4be3d29287f2f18b82846973afc142ee0bf0
